The present invention generally relates to an alloy that may be combined with water to produce hydrogen gas for energy purposes, as well as methods of producing and using the same.
Aluminum chemically reacts with water to produce hydrogen, among other byproducts, which may be a potential source of fuel. Hydrogen gas can be combusted in an engine to provide mechanical power and can be combined with oxygen in a fuel cell to produce electricity. However, corrosion of the aluminum during the reaction typically results in the formation of an oxidized exterior layer that seals the interior aluminum, limiting continued corrosion and generation of hydrogen. To overcome this oxidation phenomena, researchers have found that aluminum may be alloyed with (i.e., combined with, mixed with, coupled to) gallium to provide an aluminum alloy that still reacts with water to produce hydrogen but does not form an impermeable oxidized exterior coating. As such, contact of the alloy with water as well as moisture in the air facilitates the chemical reaction that produces hydrogen. With sufficient water, the process may continue until virtually the entire quantity of aluminum is consumed.
While presently gallium is considerably more expensive than aluminum, the gallium component of the aluminum alloy does not react with water in the above process and is not consumed. Instead, in addition to hydrogen, byproducts from the reaction include gallium and alumina. The gallium can then be separated from the alumina and alloyed again with new aluminum for continued use when the previous aluminum has been fully consumed. Drawbacks of the above process for using aluminum-gallium alloy as a source of hydrogen include the energy costs and difficulty associated with efficiently alloying the aluminum with gallium, as well as the energy costs and difficulty associated with efficiently separating the gallium from the alumina so that the gallium may be recycled and used with the new aluminum.
A need exists for a composition of matter and corresponding processes of making and using the composition of matter that allow for efficient use of aluminum alloyed with gallium to produce hydrogen from water for energy purposes. The gallium should be efficiently combined with aluminum and efficiently separated from aluminum oxide for reuse.